JP3647365B2 - Substrate unit for liquid discharge head, method for manufacturing the same, liquid discharge head, cartridge, and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate unit used in a liquid discharge head for discharging a liquid, a manufacturing method thereof, a liquid discharge head incorporating the substrate unit, the liquid discharge head, and a liquid supplied to the liquid discharge head. The present invention relates to a cartridge integrated with a liquid tank and an image forming apparatus for forming an image on a print medium. In addition to a general printing apparatus, a facsimile machine having a copying machine, a communication system, and a word processor having a printing unit Further, the present invention can be applied to an industrial recording apparatus combined with various processing apparatuses, and can also be applied to a printing apparatus and a processing apparatus such as etching.
[0002]
In this specification, “print” or “record” is not only used to form significant information such as characters and figures, but also manifests so that it can be perceived visually by humans regardless of significance. Regardless of whether or not it is, it includes a wide range of processes such as formation of images, patterns, patterns, etc. on a print medium, or etching.
[0003]
The “print medium” is not only a piece of paper used in a general printing apparatus, but also a cloth, a plastic film, a metal plate, glass, ceramics, wood, leather, etc. that can accept ink, and is in a sheet form. Three-dimensional solids other than objects, such as spheres and cylinders, are also targets.
[0004]
Further, the term “liquid” should be broadly interpreted in the same way as the definition of “print (or recording)”, and is applied to a print medium to form an image, a pattern, a pattern, or the like. And the like that are used for the etching process of the above, or the treatment of ink (for example, solidification or insolubilization of the coloring material in the ink applied to the print medium).
[0005]
[Prior art]
Among the various printing methods currently known, this is a non-impact printing method that generates almost no noise during printing, and is capable of high-speed printing, and can be printed without requiring special fixing processing on plain paper. A so-called liquid jet printing method (hereinafter referred to as an ink jet printing method) capable of performing the above is an extremely useful printing method.
[0006]
In this ink jet printing method, ink droplets such as a treatment liquid (hereinafter, collectively referred to as ink for the sake of convenience in the present specification) for adjusting the printability of the ink to the ink or the print medium are used in various operating principles. And is printed on a print medium such as paper, and the basic principle is as outlined below, as proposed in Japanese Patent Laid-Open No. 52-118798. That is, this ink-jet printing method applies a thermal pulse as an information signal to ink introduced into an ink chamber capable of containing ink, thereby causing the ink chamber to be subjected to an action force generated as the ink vaporizes and expands. In this method, ink is ejected from a communicating ejection port and ejected as ink droplets, which are attached to a print medium for printing.
[0007]
By the way, this method is easy to adapt to high-speed printing and color printing with a high-density multi-array configuration, and the configuration of the printing device is simpler than that of the conventional one. It is easy to increase the length by making full use of the advantages of IC technology and micro-machining technology that are remarkable in technological advancement and reliability improvement in the semiconductor field. This method has a wide range of applications.
[0008]
A characteristic ink jet head of the ink jet printing apparatus used in the ink jet printing method is provided with thermal energy generating means for ejecting ink from an ejection port to form flying ink droplets. This thermal energy generating means is preferably provided so as to be in direct contact with the ink in order to efficiently cause the generated thermal energy to act on the ink and to increase the on / off response speed of the thermal action of the inkjet head. It is said that.
[0009]
[Problems to be solved by the invention]
Basically, the thermal energy generating means provided in the inkjet head is composed of a heating resistor (electrothermal conversion element) layer that generates heat when energized, and a pair of electrode wirings for energizing the heating resistor layer. Therefore, when the heating resistor layer is in direct contact with the ink, depending on the electrical resistance value of the ink, electricity flows through the ink, or the ink itself is electrolyzed by the flow of electricity through the ink. Or, when the heating resistor layer is energized, the heating resistor layer reacts with the ink, and the resistance value may change due to corrosion of the heating resistor layer, or the heating resistor layer may be damaged or destroyed. It was.
[0010]
Therefore, conventionally, alloys such as Ni and Cr, ZrB₂, HfB₂The heating resistor layer is composed of an inorganic material that is relatively excellent in characteristics as a heating resistor material, such as a metal boride, etc., and the SiO layer is formed on the heating resistor layer composed of these.₂Providing a protective layer composed of a material with excellent oxidation resistance such as prevents the heating resistor layer from coming into direct contact with the ink, solves the above problems, and improves reliability and durability for repeated use. It has been proposed to try to improve.
[0011]
By the way, when forming the thermal energy generating means of such an ink jet head, it is common to sequentially stack the electrode wiring and the protective layer after forming the heating resistor layer on a predetermined substrate, In order to sufficiently perform various functions as a protective layer such as prevention of breakage of the heating resistor layer as described above or prevention of short circuit between electrode wirings, the heating resistor is used for the protective layer of such thermal energy generating means. It is required to uniformly coat the required portions of the layers and electrode wirings without having defects such as pinholes.
[0012]
Further, a second relatively thin protective layer is generally provided on the protective layer so that the protective layer and the ink are completely blocked. This protective layer is generally formed by sputtering a thin film of metal such as Ta. By providing this second protective layer, SiO₂, SiN or the like, the lower first protective layer plays a role of preventing the intrusion of ink even if a crack or the like occurs due to repeated heat generation by the heating resistor. In addition, it plays a role of cavitation protection by repeated foaming and defoaming, and by providing this second protective layer, it has been attempted to improve durability for repeated use.
[0013]
However, since this second protective layer causes cracks in the lower first protective layer due to the difference in film stress from the lower first protective layer, the region on the substrate surface where no ink is present is etched. Generally, the second protective layer is removed by the method.
[0014]
In addition, when resin is used as the discharge port forming member for forming the discharge port, the second protective layer such as Ta has extremely low adhesion to the discharge port forming member, so that the discharge port forming member is peeled off from the second protective layer. I had to do it. Therefore, in order to improve the adhesion between the substrate on which the second protective layer such as Ta is formed and the discharge port forming member, a proposal is made that a polyetheramide resin is interposed as an adhesion layer between the substrate and the discharge port forming member. (Japanese Patent Laid-Open No. 11-348290).
[0015]
In addition, as described above, since the electrode wiring is generally formed on the heating resistor layer in such an ink jet head, a step is generated between the electrode wiring and the heating resistor layer. Since unevenness of the layer thickness is likely to occur in the stepped portion, the layer must be formed so as to sufficiently cover the stepped portion in order to prevent an exposed portion from being generated. In such a state where the step coverage (hereinafter referred to as “step coverage”) is insufficient, the exposed portion of the heating resistor layer and the ink come into direct contact with each other, and the ink is electrolyzed, And the material constituting the heating resistor layer may cause a chemical reaction or the heating resistor layer may be destroyed. In addition, such a stepped portion is also likely to have a non-uniform film thickness, which causes a partial concentration of thermal stress generated in the protective layer due to repeated heat generation. This may cause cracks, and ink may enter the cracked part, resulting in the destruction of the heating resistor layer as described above. Furthermore, ink may enter from the pinholes and the heating resistor layer may be destroyed.
[0016]
Conventionally, in order to solve such a problem, it has been generally performed to increase the thickness of the protective layer to improve the step coverage or reduce the pinholes. However, increasing the protective layer is a step coverage. Although this contributes to a reduction in the number of pinholes, increasing the thickness of the protective layer hinders the supply of heat to the ink, resulting in the following new problems.
[0017]
That is, the heat generated in the heating resistor layer is transferred to the ink through the protective layer, but the thermal resistance between the protective layer surface and the heating resistor layer, which is the heat acting surface, is protected. As the layer thickness increases, it becomes necessary to apply more power load to the heating resistor layer, which is disadvantageous in terms of reducing power consumption, and more heat than necessary is stored in the substrate. A new problem arises such that the thermal responsiveness is deteriorated and the durability of the heating resistor layer is deteriorated due to the electric power more than necessary.
[0018]
Such a problem can be overcome by reducing the thickness of the protective layer. However, in the conventional inkjet head manufacturing method using a film forming method such as sputtering or vapor deposition for forming the protective layer, the step coverage is poor. Due to the above-mentioned drawbacks in durability, it has been substantially difficult to make the protective layer thin.
[0019]
In addition, it is generally known that when ink is printed on the ink jet head as described above, the ink foaming stability is improved as the ink is rapidly heated. That is, an electrical signal applied to the thermal energy generating means, generally a rectangular postponed pulse, the shorter the pulse width, the better the foam stability of the ink, thereby improving the ejection stability of the flying ink droplets. This improves the print quality. However, in the conventional ink jet head, the thickness of the protective layer must be increased as described above. For this reason, the thermal resistance of the protective layer is increased, and more heat than necessary is generated by the thermal energy generating means. In other words, the durability is deteriorated and the thermal response is lowered. For this reason, it is difficult to shorten the pulse width, and there has been a limit in improving the print quality.
[0020]
Further, as shown in FIG. 20 showing a cross-sectional structure of the substrate side of a conventional ink jet head, a heating resistor layer 13 is laminated on the surface of the oxide layer 12 formed on the surface portion of the substrate 11 by a sputtering method. At least a pair of electrode wirings 14a and 14b connected to the resistor layer 13 is formed. Reference numeral 15 denotes a step formed by the electrode wirings 14 a and 14 b and rising from the heating resistor layer 13.
[0021]
In such a configuration, as described above, the lower first protective layer 17 covered with the second protective layer 16 is likely to have defects such as pinholes, and the electrode wirings 14a and 14b are likely to be exposed at the stepped portion 15. The lower first protective layer 17 had to be thicker than necessary (usually more than twice the thickness of the electrode wirings 14a and 14b) so as to sufficiently cover the step portion 15.
[0022]
For this reason, proposals have been made to reduce the thickness of the lower first protective layer 17 without deteriorating the step coverage. For example, JP-A-60-234850 proposes bias sputtering with good step coverage as a method of forming the lower first protective layer 17, and JP-A-62-45283 and 45237 disclose a lower first protective layer 17. 1 It has been proposed to improve the step coverage by changing the shape of the step by etching back or sputter etching after forming the protective layer 17, and JP-A-62-45286 discloses reflowing the protective film. It has been proposed to improve step coverage.
[0023]
However, bias sputtering has poor film thickness stability and has disadvantages such as generation of dust from around the target. In addition, methods such as etch back, sputter edge, and reflow cause an increase in the number of processes and increase costs.
[0024]
As another method, as shown in FIG. 21, which shows a cross-sectional structure of a substrate portion of a conventional inkjet head, the HP journal can improve the step coverage of the protective film 15 by making the cross-sectional shape of the electrode wirings 14a and 14b tapered. Proposed in the May 1985 issue. It has also been proposed to etch a resist simultaneously with the electrode wirings 14a and 14b by using a developer which is an alkaline solution. Note that the members having the same functions as those in FIG.
[0025]
However, according to these methods, the uniformity and reproducibility of the stepped portion 15 due to the tapered shape are poor, which is disadvantageous particularly in the case of a large substrate 11 or the like. In particular, when the uniformity of the stepped portion 15 due to the tapered shape is poor, the following problems occur.
[0026]
That is, in the place where the taper angle of the step portion 15 is steep, the step coverage is insufficient and the above-described problem occurs. Further, in places where the taper angle is loose, the width and cross-sectional area of the electrode wirings 14a and 14b are reduced, and the electric resistance is higher than that of other portions. The problem of adversely affecting the print quality and the like when configured as a problem arises.
[0027]
As another method, a method of selectively thinning the protective film 15 on the heating resistor layer 13 has been put into practical use as shown in FIG. 22 showing a cross-sectional structure of a substrate portion of a conventional inkjet head. The members having the same functions as those in FIG. 20 are denoted by the same reference numerals.
[0028]
However, this method requires two steps of forming the protective films 15a and 15b, which are insulators after the electrode wirings 14a and 14b are formed, and uses a photomask to selectively thin the region. The exposure must be performed, resulting in an increase in the number of processes. In addition, since the inside of the heat generating region is selectively thinned, there is a disadvantage that the thermal efficiency is poor at the outer peripheral portion.
[0029]
OBJECT OF THE INVENTION
An object of the present invention is to make the first protective layer above the heating resistor as thin as possible and reduce the film thickness of the electrode wiring and wiring layer of the heating resistor to damage the first protective layer and the wiring layer. It is another object of the present invention to provide a liquid discharge head substrate unit that improves the foaming stability due to rapid heating of ink and at the same time increases the durability by removing the second protective layer.
[0030]
Another object of the present invention is to provide a highly reliable liquid discharge which further improves the adhesion between the discharge port forming member and a substrate in which such a liquid discharge substrate unit is incorporated and a protective layer such as Ta is exposed. To provide a head.
[0031]
Still another object of the present invention is to provide a method, a cartridge, and an image forming apparatus for manufacturing such a liquid discharge head substrate unit.
[0032]
[Means for Solving the Problems]
  A first aspect of the present invention is a substrate unit used in a liquid discharge head that applies thermal energy to a liquid to cause film boiling, and thereby discharges droplets from the discharge port. An electrothermal conversion element formed to generate thermal energy, a pair of electrode wirings formed on the surface portion of the substrate so as to be electrically connected to the electrothermal conversion element, and substantially over the entire surface portion of the substrate A first protective layer formed to cover the pair of electrode wirings and the electrothermal conversion element; and the electrothermal conversion element, the electrothermal conversion element and the pair of electrode wirings formed on a surface of the first protective layer. A thickness of the pair of electrode wiringsButThe thickness of the portion of the first protective layer that is in the range of 1800-2400 mm and is covered by the second protective layerButIn the range of 2600-3400 km,The first protective layer includesNot covered by the second protective layerHaving a uniform film thickness,Of the first protective layerUniform film thicknessThe thickness of the part is smaller than the thickness of the part of the first protective layer covered with the second protective layer.
[0033]
According to the present invention, the first protective layer is formed in a uniform thin film thickness without adding a film forming process or using a mask, and is formed by the electrode wiring, and the first protection in the stepped portion rising from the surface of the substrate. The coverage of the stratum is kept good.
[0034]
  A second aspect of the present invention is a method for manufacturing a substrate unit used in a liquid discharge head for applying liquid energy to a liquid to cause film boiling and thereby discharging liquid droplets from a discharge port. On the surface,Forming an electrothermal conversion element for generating thermal energy; forming a pair of electrode wirings on a surface portion of the substrate so as to conduct to the electrothermal conversion element; the pair of electrode wirings; and Forming a first protective layer having a thickness of 2600 to 3400 covering the electrothermal conversion element over substantially the entire surface of the substrate; and the electrothermal conversion element, the electrothermal conversion element, and the pair of electrode wirings By forming a second protective layer covering the vicinity of the connection portion on the surface of the first protective layer by dry etching, the thickness of the portion of the first protective layer not covered by the second protective layer is set to the second The thickness of the pair of electrode wirings is in the range of 1800 to 2400 mm, and the step of reducing the thickness of the first protective layer covered by the protective layer. It is.
[0035]
According to the present invention, when the second protective layer is formed by dry etching, damage to the electrothermal conversion element and the pair of electrode wirings is prevented.
[0036]
  The third aspect of the present invention is:A liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port.An electrothermal conversion element that is formed on the substrate and generates thermal energy for causing film boiling in the liquid; a pair of electrode wirings that are formed on the substrate and that conduct to the electrothermal conversion element; and a surface portion of the substrate A first protective layer that covers the pair of electrode wirings and the electrothermal conversion element, and is formed on a surface of the first protective layer to form the electrothermal conversion element, the electrothermal conversion element, and the A second protective layer that covers the vicinity of the connection portion between the pair of electrode wirings, the thickness of the pair of electrode wirings is in the range of 1800 to 2400 mm, and the first protective layer is covered by the second protective layer. Part thicknessButIn the range of 2600-3400 km,The first protective layer includesNot covered by the second protective layerHave a uniform thickness,Of the first protective layerUniform film thicknessThe thickness of the portion is smaller than the thickness of the portion of the first protective layer covered by the second protective layer.With thingsis there.
[0037]
  The fourth aspect of the present invention isA cartridge having a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port,
  An electrothermal conversion element that is formed on the substrate and generates thermal energy for causing film boiling in the liquid; a pair of electrode wirings that are formed on the substrate and that conduct to the electrothermal conversion element; and a surface portion of the substrate A first protective layer having a thickness that covers the pair of electrode wirings and the electrothermal conversion element, and the electrothermal conversion element and the electrothermal conversion element formed on the surface of the first protective layer. And a liquid discharge head having a second protective layer covering the vicinity of the connection portion between the pair of electrode wirings,
  A liquid tank for storing liquid supplied to the liquid discharge head,
  The thickness of the first protective layer covered with the second protective layer, wherein the thickness of the pair of electrode wirings is in the range of 1800 to 2400 mmButIn the range of 2600-3400 km,The first protective layer includesNot covered by the second protective layerHave a uniform thickness,Of the first protective layerUniform film thicknessThe thickness of the portion is smaller than the thickness of the portion of the first protective layer covered by the second protective layer.With thingsis there.
[0038]
  The fifth aspect of the present invention is:An image forming apparatus using a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port.
  An electrothermal conversion element that generates thermal energy for causing film boiling in the liquid formed on the substrate, a pair of electrode wirings formed on the substrate and conducting to the electrothermal conversion element, and a surface portion of the substrate A first protective layer that is formed over substantially the entire area and covers the pair of electrode wirings and the electrothermal conversion element; and the electrothermal conversion element, the electrothermal conversion element, and the pair that are formed on the surface of the first protective layer. And a second protective layer covering the vicinity of the connection portion with the electrode wiringSaidIt has a mounting part for the liquid discharge head,
  The thickness of the pair of electrode wires is in the range of 1800 to 2400 mm.RThe thickness of the portion of the first protective layer covered by the second protective layerButIn the range of 2600-3400 km,The first protective layer includesNot covered by the second protective layerHave a uniform thickness,Of the first protective layerUniform film thicknessPart thicknessIsThe thickness of the portion of the first protective layer covered with the second protective layer is thinner.With thingsis there.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
  In the liquid discharge head substrate unit according to the first aspect of the present invention, the thickness of the pair of electrode wirings is preferably in the range of 2000 to 2200 mm, and the first protective layer is not covered by the second protective layer.Uniform film thicknessThe difference between the thickness of the portion and the thickness of the portion of the first protective layer covered by the second protective layer may be in the range of 100 to 200 mm. The thickness of the first protective layer may be 1.08 times or more the thickness of the pair of electrode wirings.
[0040]
In the method of manufacturing the substrate unit for a liquid discharge head according to the second aspect of the present invention, when the second protective layer is formed by dry etching, the portion of the first protective layer not covered by the second protective layer is etched. The thickness can be in the range of 100 to 200 mm.
[0041]
  In the liquid discharge head according to the third aspect of the present invention, a discharge port forming member for forming a discharge port is further provided, and the discharge port forming member is not covered with a part of the second protective layer and the second protective layer. A part of the first protective layer and a part of the first protective layer not covered by the second protective layer may be joined via an adhesion layer. In this case, the first protective layer and the second protective layer in the vicinity of the boundary between the portion of the first protective layer covered by the second protective layer and the portion of the first protective layer not covered by the second protective layer. The portion preferably has a tapered shape, and this tapered shape is2More than the angle of the taper shape of the protective layer1More preferably, the angle of the protective layer taper is more gradual. The adhesion layer may be a polyetheramide resin, and the polyetheramide resin may be thermoplastic. The discharge port forming member may be a resin, and may be formed of a cationic polymerization cured product of an epoxy resin. The discharge ports can also be provided on the opposite sides of the electrothermal conversion elements, and the discharge ports are formed in at least two rows in parallel with each other, arranged at intervals of 600 dpi, and these arrangement intervals for each row are half-pitch to each other. It may be shifted. In addition, the liquid is inkAndIt may be a treatment liquid that adjusts the printability of this ink ejected to the print medium, and the liquid from the ejection port that is ejected by the drive pulse applied to the electrothermal conversion element.Per timeThe discharge amount may be 5 picoliters or less.
[0042]
In the cartridge according to the fourth aspect of the present invention, the liquid tank may be detachably mounted on the liquid discharge head. The liquid discharge head further includes a discharge port forming member in which a discharge port is formed. The discharge port forming member is a part of the second protective layer and a portion of the first protective layer that is not covered by the second protective layer. You may make it join to through an adhesion layer.
[0043]
In the image forming apparatus according to the fifth aspect of the present invention, the attachment portion of the liquid ejection head has a carriage that can be scanned and moved in a direction intersecting the conveyance direction of the print medium from which the liquid is ejected from the liquid ejection head. It's okay. The liquid discharge head may be detachably mounted on the carriage via an attaching / detaching unit. The liquid discharge head further includes a discharge port forming member in which a discharge port is formed. The discharge port forming member is formed on a part of the second protective layer and a portion of the first protective layer that is not covered by the second protective layer. You may make it join through an adhesion layer.
[0044]
【Example】
Embodiments in which the present invention is applied to an ink jet printer will be described in detail with reference to FIGS. 1 to 19, but the present invention is not limited to such embodiments, and these may be further combined, or patents in this specification may be described. The present invention can be applied to other technologies to be included in the concept of the present invention described in the claims.
[0045]
[Device main unit]
1 and 2 show a schematic configuration of a printer using the ink jet recording method. In FIG. 1, an apparatus main body M1000 that forms the outer shell of a printer in this embodiment includes a lower case M1001, an upper case M1002, an access cover M1003, an exterior member of a discharge tray M1004, and a chassis M3019 ( (See FIG. 2).
[0046]
The chassis M3019 is composed of a plurality of plate-shaped metal members having a predetermined rigidity, forms a skeleton of the recording apparatus, and holds each recording operation mechanism described later.
[0047]
The lower case M1001 forms a substantially lower half portion of the apparatus main body M1000, and the upper case M1002 forms a substantially upper half portion of the apparatus upper body M1000, and each mechanism described later is housed in a combination of both cases. A hollow body structure having a storage space is formed, and an opening is formed in each of an upper surface portion and a front surface portion thereof.
[0048]
Further, one end of the discharge tray M1004 is rotatably held by the lower case M1001, and an opening formed on the front surface of the lower case M1001 can be opened and closed by the rotation. For this reason, when executing the recording operation, the discharge tray M1004 is rotated to the front side to open the opening so that the recording sheets can be discharged and the discharged recording sheets P are sequentially stacked. It has come to be able to do. In addition, the discharge tray M1004 contains two auxiliary trays M1004a and M1004b. By pulling out each tray as needed, the sheet support area can be expanded or reduced in three stages. It has become.
[0049]
One end of the access cover M1003 is rotatably held by the upper case M1002, and can open and close an opening formed on the upper surface. By opening the access cover M1003, the access cover M1003 is housed inside the main body. It is possible to replace the print head cartridge H1000 or the ink tank H1900. Although not specifically shown here, when the access cover M1003 is opened and closed, the protrusion formed on the back surface rotates the cover opening and closing lever, and the rotation position of the lever is detected by a micro switch or the like. Thus, the open / closed state of the access cover can be detected.
[0050]
On the upper surface of the rear part of the upper case M1002, a power key E0018 and a resume key E0019 are provided so that they can be pressed, and an LED E0020 is provided. When the power key E0018 is pressed, the LED E0020 is lit and recording is possible. This is to inform the operator. Further, the LED E0020 has various display functions such as flashing and changing the color, and leveling the buzzer E0021 (FIG. 7) to notify the operator of a printer trouble or the like. When the trouble is solved, the recording is resumed by pressing the resume key E0019.
[0051]
[Recording mechanism]
Next, the recording operation mechanism in the present embodiment that is housed and held in the printer main body M1000 will be described.
[0052]
As a recording operation mechanism in the present embodiment, an automatic feeding unit M3022 that automatically feeds the recording sheet P into the apparatus main body, and a desired recording sheet P that is sent one by one from the automatic feeding unit. A conveyance unit M3029 for guiding the recording sheet P from the recording position to the discharge unit M3030, a recording unit for performing desired recording on the recording sheet P conveyed to the conveyance unit M3029, and a recovery process for the recording unit It is comprised from the recovery part M5000 which performs.
[0053]
(Recording part)
Here, the recording unit will be described.
The carriage M4001 is movably supported by a carriage shaft M4021, and the recording head cartridge H1000 is detachably mounted on the carriage M4001.
[0054]
Recording head cartridge
First, the recording head cartridge will be described with reference to FIGS.
[0055]
As shown in FIG. 3, the recording head cartridge H1000 in this embodiment has an ink tank H1900 that stores ink, and a recording head H1001 that discharges ink supplied from the ink tank H1900 from nozzles according to recording information. The recording head H1001 adopts a so-called cartridge system that is detachably mounted on a carriage M4001 described later.
[0056]
In the recording head cartridge H1000 shown here, in order to enable high-quality color recording with a photographic tone, as ink tanks, for example, black, light cyan, light magenta, cyan, magenta, and yellow, independent ink tanks are prepared. As shown in FIG. 4, each is detachable from the recording head H1001.
[0057]
As shown in the exploded perspective view of FIG. 5, the recording head H1001 includes a recording element substrate H1100, a first plate H1200, an electric wiring substrate H1300, a second plate H1400, a tank holder H1500, a flow path forming member H1600, The filter H1700 and the seal rubber H1800 are included.
[0058]
In the recording element substrate H1100, a plurality of recording elements for ejecting ink to one side of the Si substrate and electric wiring such as Al for supplying electric power to each recording element are formed by a film forming technique. A plurality of corresponding ink channels and a plurality of ejection ports H1100T are formed by photolithography, and ink supply ports for supplying ink to the plurality of ink channels are formed to open on the back surface. . The recording element substrate H1100 is bonded and fixed to the first plate H1200, and an ink supply port H1201 for supplying ink to the recording element substrate H1100 is formed here. Further, a second plate H1400 having an opening is bonded and fixed to the first plate H1200, and the electric wiring board H1300 and the recording element substrate H1100 are electrically connected to the second plate H1400. Thus, the electric wiring board H1300 is held. The electrical wiring substrate H1300 applies an electrical signal for ejecting ink to the recording element substrate H1100. The electrical wiring substrate H1300 is located at an end portion of the electrical wiring and corresponds to the electrical wiring from the main body. It has an external signal input terminal H1301 for receiving signals, and the external signal input terminal H1301 is positioned and fixed on the back side of a tank holder H1500 described later.
[0059]
On the other hand, a flow path forming member H1600 is ultrasonically welded to a tank holder H1500 that detachably holds the ink tank H1900, thereby forming an ink flow path H1501 extending from the ink tank H1900 to the first plate H1200. In addition, a filter H1700 is provided at an end of the ink flow path H1501 that engages with the ink tank H1900 on the ink tank side so that entry of dust from the outside can be prevented. Further, a seal rubber H1800 is attached to the engaging portion with the ink tank H1900 so that ink can be prevented from evaporating from the engaging portion.
[0060]
Further, as described above, the tank holder portion composed of the tank holder H1500, the flow path forming member H1600, the filter H1700, and the seal rubber H1800, the recording element substrate H1100, the first plate H1200, the electric wiring substrate H1300, and the second plate. The recording head H1001 is configured by bonding the recording element unit including the H1400 with an adhesive or the like.
[0061]
carriage
Next, the carriage M4001 will be described with reference to FIG.
[0062]
As shown in the figure, the carriage M4001 engages with the carriage M4001, engages with the carriage cover M4002 for guiding the recording head H1001 to the mounting position of the carriage M4001, and the tank holder H1500 of the recording head H1001, and the recording head H1001. Is provided with a head set lever M4007 for pressing to set at a predetermined mounting position.
[0063]
That is, the head set lever M4007 is provided at the upper part of the carriage M4001 so as to be rotatable with respect to the head set lever shaft, and a head set plate (not shown) is provided via a spring at the engaging portion with the recording head H1001. The recording head H1001 is pressed by the spring force and is mounted on the carriage M4001.
[0064]
Further, a contact flexible printed cable (hereinafter referred to as a contact FPC) E0011 is provided at another engagement portion of the carriage M4001 with the recording head H1001, and a contact portion on the contact FPC E0011 and a contact provided on the recording head H1001. The unit (external signal input terminal) H1301 is in electrical contact so that various information for recording can be exchanged and power can be supplied to the recording head H1001.
[0065]
Here, an elastic member such as rubber (not shown) is provided between the contact portion of the contact FPC E0011 and the carriage M4001, and the contact portion and the carriage M4001 are connected by the elastic force of the elastic member and the pressing force by the headset lever spring. It is designed to enable reliable contact. Further, the contact FPC E0011 is connected to a carriage substrate E0013 mounted on the back surface of the carriage M4001 (see FIG. 7).
[0066]
[Scanner]
The printer in this embodiment can also be used as a reading device by replacing the scanner with a recording head.
[0067]
The scanner moves together with the carriage on the printer side, and reads a document image fed in place of the recording medium in the sub-scanning direction, and alternately performs the reading operation and the document feeding operation. Thus, one piece of document image information is read.
[0068]
FIG. 6 is a diagram showing a schematic configuration of the scanner M6000.
[0069]
As shown in the figure, the scanner holder M6001 has a box shape, and an optical system and a processing circuit necessary for reading are accommodated therein. Further, when the scanner M6000 is mounted on the carriage M4001, a scanner reading lens M6006 is provided at a portion facing the document surface, from which a document image is read. The scanner illumination lens M6005 has a light source (not shown) inside, and light emitted from the light source is irradiated onto the document.
[0070]
A scanner cover M6003 fixed to the bottom of the scanner holder M6001 is fitted so as to shield the inside of the scanner holder M6001, and a louver-shaped grip portion provided on the side surface improves the detachable operability to the carriage M4001. Yes. The outer shape of the scanner holder M6001 is substantially the same as that of the recording head H1001, and it can be attached to and detached from the carriage M4001 by the same operation as that of the recording head cartridge H1000.
[0071]
The scanner holder M6001 accommodates a substrate having a processing circuit, and a scanner contact PCB connected to the substrate is exposed to the outside. When the scanner M6000 is mounted on the carriage M4001, The scanner contact PCB M6004 contacts the contact FPC E0011 on the carriage M4001 side, and the substrate is electrically connected to the control system on the main body side via the carriage M4001.
[0072]
Next, an electrical circuit configuration in the embodiment of the present invention will be described.
[0073]
FIG. 7 is a diagram schematically showing the overall configuration of the electrical circuit in this embodiment.
[0074]
The electrical circuit in this embodiment is mainly configured by a carriage substrate (CRPCB) E0013, a main PCB (Printed Circuit Board) E0014, a power supply unit E0015, and the like.
[0075]
Here, the power supply unit is connected to the main PCB E0014 and supplies various drive power sources.
[0076]
The carriage substrate E0013 is a printed circuit board unit mounted on the carriage M4001 (FIG. 2). The carriage substrate E0013 functions as an interface for transmitting and receiving signals to and from the recording head through the contact FPC E0011, and an encoder according to the movement of the carriage M4001. Based on the pulse signal output from the sensor E0004, a change in the positional relationship between the encoder scale E0005 and the encoder sensor E0004 is detected, and the output signal is output to the main PCB E0014 through a flexible flat cable (CRFFC) E0012.
[0077]
Further, the main PCB is a printed circuit board unit that controls driving of each part of the ink jet recording apparatus according to this embodiment, and includes a paper edge detection sensor (PE sensor) E0007, an ASF sensor E0009, a cover sensor E0022, a parallel interface (parallel I / F). ) E0016, serial interface (serial I / F) E0017, resume key E0019, LED E0020, power key E0018, buzzer E0021, etc. on the board, and further CR motor E0001, LF motor E0002, PG motor In addition to controlling these drives connected to E0003, connection interfaces with ink out sensor E0006, GAP sensor E0008, PG sensor E0010, CRFFC E0012, and power supply unit E0015 are connected. Has a face.
[0078]
FIG. 8 is a block diagram showing the internal configuration of the main PCB.
[0079]
In the figure, E1001 is a CPU, and this CPU E1001 has an oscillator OSC E1002 inside, and is connected to an oscillation circuit E1005 to generate a system clock by its output signal E1019. In addition, it is connected to a ROM E1004 and an ASIC (Application Specific Integrated Circuit) E1006 through a control bus E1014, and controls an ASIC, an input signal E1017 from a power key, and an input signal E1016 from a resume key according to a program stored in the ROM. The state of the detection signal E1042, the head detection signal (HSENS) E1013 is detected, and the buzzer E0021 is further driven by the buzzer signal (BUZ) E1018, and the ink out detection signal (INKS) connected to the built-in A / D converter E1003. ) While detecting the state of E1011 and the thermistor temperature detection signal (TH) E1012, other various logical operations and condition determinations are performed to control the drive of the ink jet recording apparatus.
[0080]
Here, the head detection signal E1013 is a head mounting detection signal input from the recording head cartridge H1000 via the flexible flat cable E0012, the carriage substrate E0013, and the contact flexible print cable E0011, and the ink end detection signal is the ink end sensor E0006. The thermistor temperature detection signal E1012, which is an analog signal output from, is an analog signal from a thermistor (not shown) provided on the carriage substrate E0013.
[0081]
E1008 is a CR motor driver, which uses a motor power source (VM) E1040 as a drive source, generates a CR motor drive signal E1037 in accordance with a CR motor control signal E1036 from the ASIC E1006, and drives the CR motor E0001. E1009 is an LF / PG motor driver, which uses a motor power source E1040 as a drive source, generates an LF motor drive signal E1035 according to a pulse motor control signal (PM control signal) E1033 from the ASIC E1006, and drives the LF motor thereby At the same time, a PG motor drive signal E1034 is generated to drive the PG motor.
[0082]
E1010 is a power supply control circuit that controls power supply to each sensor having a light emitting element in accordance with a power supply control signal E1024 from the ASIC E1006. The parallel I / F E0016 transmits the parallel I / F signal E1030 from the ASIC E1006 to the parallel I / F cable E1031 connected to the outside, and transmits the signal of the parallel I / F cable E1031 to the ASIC E1006. The serial I / F E0017 transmits the serial I / F signal E1028 from the ASIC E1006 to the serial I / F cable E1029 connected to the outside, and transmits the signal from the cable E1029 to the ASIC E1006.
[0083]
On the other hand, a head power supply (VH) E1039, a motor power supply (VM) E1040, and a logic power supply (VDD) E1041 are supplied from the power supply unit E0015. Further, a head power ON signal (VHON) E1022 and a motor power ON signal (VMOM) E1023 from the ASIC E1006 are input to the power supply unit E0015 to control on / off of the head power E1039 and the motor power E1040, respectively. The logic power supply (VDD) E1041 supplied from the power supply unit E0015 is voltage-converted as necessary, and then supplied to each part inside and outside the main PCB E0014.
[0084]
The head power supply E1039 is smoothed on the main PCB E0014 and then sent to the flexible flat cable E0011 to be used for driving the recording head cartridge H1000.
[0085]
E1007 is a reset circuit that detects a decrease in the logic power supply voltage E1040, supplies a reset signal (RESET) E1015 to the CPU E1001 and the ASIC E1006, and performs initialization.
[0086]
The ASIC E1006 is a one-chip semiconductor integrated circuit, and is controlled by the CPU E1001 through the control bus E1014. The above-described CR motor control signal E1036, PM control signal E1033, power supply control signal E1024, head power supply ON signal E1022, and motor power supply ON. In addition to outputting the signal E1023 and the like and exchanging signals with the parallel I / F E0016 and serial I / F E0017, the PE detection signal (PES) E1025 from the PE sensor E0007 and the ASF detection signal (ASFS from the ASF sensor E0009) ) E1026, the GAP detection signal (GAPS) E1027 from the GAP sensor E0008, and the PG detection signal (PGS) E1032 from the PG sensor E0007 are detected, and the data representing the state is transmitted to the control bus E1014. Through transmitted to CPU E1001 by, CPU E1001 based on the input data performs blinking LED E0020 controls the driving of an LED drive signal E1038. Further, the state of the encoder signal (ENC) E1020 is detected to generate a timing signal, and the head control signal E1021 is used to interface with the recording head cartridge H1000 to control the recording operation. Here, the encoder signal (ENC) E1020 is an output signal of the CR encoder sensor E0004 inputted through the flexible flat cable E0012. The head control signal E1021 is supplied to the recording head H1000 via the flexible flat cable E0012, the carriage substrate E0013, and the contact FPC E0011.
[0087]
FIG. 9 is a block diagram showing the internal configuration of the ASIC E1006. In the figure, the connection between each block shows only the flow of data related to the control of the head and each mechanism component, such as recording data and motor control data. Such control signals, clocks, and control signals related to DMA control are omitted in order to avoid complications described in the drawings.
[0088]
In FIG. 9, E2002 is a PLL, and a clock (illustrated) supplied to most of the ASIC E1006 by a clock signal (CLK) E2031 and a PLL control signal (PLLON) E2033 output from the CPU E1001 as shown in FIG. Not).
[0089]
Further, E2001 is a CPU interface (CPU I / F), which is controlled by a reset signal E1015, a soft reset signal (PDWN) E2032, a clock signal (CLK) E2031, and a control signal from the control bus E1014. Performs control such as register read / write for each block as described, supplies clocks to some blocks, accepts interrupt signals (not shown), and outputs an interrupt signal (INT) E2034 to the CPU E1001 Then, the occurrence of an interrupt in the ASIC E1006 is notified.
[0090]
E2005 is a DRAM having areas such as a reception buffer E2010, a work buffer E2011, a print buffer E2014, and a development data buffer E2016 as recording data buffers, and a motor control buffer E2023 for motor control. Further, as buffers used in the scanner operation mode, areas such as a scanner take-in buffer E2024, a scanner data buffer E2026, and a send buffer E2028 are provided in place of the recording data buffers described above.
[0091]
The DRAM E2005 is also used as a work area necessary for the operation of the CPU E1001. That is, E2004 is a DRAM control unit, which switches between access from the CPU E1001 to the DRAM E2005 via the control bus and access from the DMA control unit E2003 to the DRAM E2005, which will be described later, and performs a read / write operation to the DRAM E2005.
[0092]
The DMA control unit E2003 receives a request (not shown) from each block, and in the case of a write operation in the case of a write operation (E2038, E2041, E2044, E2053, E2055) and E2057 in the case of a write operation. ) Etc. are output to the RAM control unit to perform DRAM access. In the case of reading, read data (E2040, E2043, E2045, E2051, E2054, E2056, E2058, and E2059) from the DRAM control unit E2004 is transferred to the request source block.
[0093]
Further, E2006 is 1284 I / F. Under the control of the CPU E1001 via the CPU I / F E2001, the parallel I / F E0016 provides a bidirectional communication interface with an external host device (not shown). Data received from E0016 (PIF reception data E2036) is transferred to the reception control unit E2008 by DMA processing, and data stored in the transmission buffer E2028 in the DRAM E2005 (1284 transmission data (RDPIF) E2059) is subjected to DMA processing at the time of scanner reading. To the parallel I / F.
[0094]
E2007 is a USB I / F, which performs a bidirectional communication interface with an external host device (not shown) through the serial I / F E0017 under the control of the CPU E1001 via the CPU I / F E2001, and from the serial I / F E0017 during printing. The received data (USB received data E2037) is transferred to the reception control unit E2008 by DMA processing, and the data (USB transmitted data (RDUSB) E2058) stored in the transmission buffer E2028 in the DRAM E2005 is serialized by DMA processing when the scanner reads. / F Send to E0017. The reception control unit E2008 writes the reception data (WDIF) E2038) from the I / F selected from the 1284 I / F E2006 or USB I / F E2007 to the reception buffer write address managed by the reception buffer control unit E2039.
[0095]
E2009 is a compression / decompression DMA, and the reception data (raster data) stored in the reception buffer E2010 is read from the reception buffer read address managed by the reception buffer control unit E2039 under the control of the CPU E1001 via the CPU I / F E2001. The data (RDWK) E2040 is compressed / expanded in accordance with the designated mode, and written as a recording code string (WDWK) E2041 in the work buffer area.
[0096]
E2013 is a recording buffer transfer DMA, which reads out the recording code (RDWP) E2043 on the work buffer E2011 under the control of the CPU E1007 via the CPU I / F E2001, and each recording code is suitable for the data transfer order to the recording head cartridge H1000. The data are rearranged to the addresses on the print buffer E2014 and transferred (WDWP E2044). E2012 is a work clear DMA, and the designated work fill data (WDWF) E2042 is assigned to the area on the work buffer that has been transferred by the recording buffer transfer DMA E2015 under the control of the CPU E1001 via the CPU I / F E2001. Write repeatedly.
[0097]
E2015 is a recording data expansion DMA, and recording codes written rearranged on the print buffer are triggered by the data expansion timing signal E2050 from the head controller E2018 under the control of the CPU E1001 via the CPU I / F E2001. And the development data written on the development data buffer E2016 are read out to generate development recording data (RDHDG) E2045, which is written into the column buffer E2017 as column buffer write data (WDHDG) E2047. Here, the column buffer E2017 is an SRAM that temporarily stores transfer data (development recording data) to the recording head cartridge H1000, and a shake hand signal (not shown) between the recording data expansion DMA and the head control unit. Are shared and managed by both blocks.
[0098]
Reference numeral E2018 denotes a head controller, which controls the CPU E1001 via the CPU I / F E2001 to interface with the recording head cartridge H1000 or the scanner via a head control signal, and also outputs a head drive timing signal from the encoder signal processor E2019. Based on E2049, a data expansion timing signal E2050 is output to the recording data expansion DMA.
[0099]
Further, at the time of printing, the developed recording data (RDHD) E2048 is read from the column buffer according to the head driving timing signal E2049, and the data is output to the recording head cartridge H1000 through the head control signal E1021.
[0100]
In the scanner reading mode, the take-in data (WDHD) E2053 input through the head control signal E1021 is DMA-transferred to the scanner take-in buffer E2024 on the DRAM E2005. E2025 is a scanner data processing DMA, which is a process in which the acquisition buffer read data (RDAV) E2054 stored in the scanner acquisition buffer E2024 is read out and subjected to processing such as averaging under the control of the CPU E1001 via the CPU I / F E2001. The completed data (WDAV) E2055 is written into the scanner data buffer E2026 on the DRAM E2005.
[0101]
E2027 is a scanner data compression DMA. Under the control of the CPU E1001 via the CPU I / F E2001, the processed data (RDYC) E2056 on the scanner data buffer E2026 is read and compressed, and compressed data (WDYC) E2057 is read. Write and transfer to the send buffer E2028.
[0102]
E2019 is an encoder signal processing unit that receives the encoder signal (ENC) and outputs a head drive timing signal E2049 according to a mode determined by the control of the CPU E1001, and in addition to the position and speed of the carriage M4001 obtained from the encoder signal E1020. The relevant information is stored in a register and provided to the CPU E1001. Based on this information, the CPU E1001 determines various parameters in the control of the CR motor E0001. Reference numeral E2020 denotes a CR motor control unit which outputs a CR motor control signal E1036 under the control of the CPU E1001 via the CPU I / F E2001.
[0103]
E2022 is a sensor signal processing unit which receives each detection signal output from the PG sensor E0010, PE sensor E0007, ASF sensor E0009, GAP sensor E0008, etc., and stores the sensor information according to the mode defined by the control of the CPU E1001. In addition to transmitting to E1001, a sensor detection signal E2052 is output to the LF / PG motor control unit DMA E2021.
[0104]
The LF / PG motor control DMAE 2021 reads the pulse motor drive table (RDPM) E2051 from the motor control buffer E2023 on the DRAM E2005 and outputs the pulse motor control signal E under the control of the CPU E1001 via the CPU I / F E2001. Depending on the operation mode, a pulse motor control signal E1033 is output using the sensor detection signal as a control trigger.
[0105]
E2030 is an LED control unit that outputs an LED drive signal E1038 under the control of the CPU E1001 via the CPU I / F E2001. Further, E2029 is a port control unit that outputs a head power ON signal E1022, a motor power ON signal E1023, and a power control signal E1024 under the control of the CPU E1001 via the CPU I / F E2001.
[0106]
Next, the operation of the ink jet recording apparatus according to the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.
[0107]
When the apparatus is connected to the AC power source, first, in step S1, a first initialization process of the apparatus is performed. In this initialization process, an electrical circuit system check such as a ROM and RAM check of the apparatus is performed to confirm whether or not the apparatus can operate normally.
[0108]
Next, in step S2, it is determined whether the power key E0018 provided on the upper case M1002 of the apparatus body M1000 is turned on. If the power key E0018 is pressed, the process proceeds to the next step S3. Here, a second initialization process is performed.
[0109]
In this second initialization process, various drive mechanisms and head systems of this apparatus are checked. That is, when initializing various motors and reading head information, it is confirmed whether this apparatus can operate normally.
[0110]
In step S4, an event is waited for. That is, a command event from an external I / F, a panel key event by a user operation, an internal control event, and the like are monitored for this apparatus, and when these events occur, processing corresponding to the event is executed.
[0111]
For example, if a print command event from the external I / F is received in step S4, the process proceeds to step S5. If a power key event is generated by a user operation in the same step, the process proceeds to step S10. If another event occurs in the step, the process proceeds to step S11.
[0112]
In step S5, the print command from the external I / F is analyzed to determine the specified paper type, paper size, print quality, paper feed method, and the like, and data representing the determination result is stored in the RAM in the apparatus. E2005 is stored, and the process proceeds to step S6.
[0113]
Next, in step S6, paper feeding is started by the paper feeding method specified in step S5, the paper is sent to the recording start position, and the process proceeds to step S7.
[0114]
In step S7, a recording operation is performed. In this recording operation, the recording data sent from the external I / F is temporarily stored in the recording buffer, and then the CR motor E0001 is driven to start the movement of the carriage M4001 in the scanning direction and is stored in the print buffer E2014. The supplied recording data is supplied to the recording head H1001 to record one line. When the recording operation for one line of recording data is completed, the LF motor E0002 is driven and the LF roller M3001 is rotated to feed the paper. Send in the sub-scanning direction. Thereafter, the above operation is repeatedly executed, and when the recording of one page of recording data from the external I / F is completed, the process proceeds to step 8.
[0115]
In step S8, the LF motor E0002 is driven, the paper discharge roller M2003 is driven, and the paper feeding is repeated until it is determined that the paper is completely sent out from the apparatus. When the paper is finished, the paper is placed on the paper discharge tray M1004a. The paper is completely discharged.
[0116]
Next, in step S9, it is determined whether or not the recording operation for all the pages to be recorded has been completed. If pages to be recorded remain, the process returns to step S5. The above operations are repeated, and when the recording operation for all the pages to be recorded is completed, the recording operation ends, and then the process proceeds to step S4 to wait for the next event.
[0117]
On the other hand, in step S10, printer termination processing is performed to stop the operation of the apparatus. That is, in order to turn off the power of various motors and heads, the power supply is turned off, and then the power is turned off and the process proceeds to step S4 to wait for the next event.
[0118]
In step S11, event processing other than the above is performed. For example, processing corresponding to a recovery command from various panel keys of this apparatus or an external I / F, or a recovery event that occurs internally is performed. After the process is completed, the process proceeds to step S4 and waits for the next event.
[0119]
Hereinafter, the present invention will be described in more detail with reference to examples.
[0120]
Example 1
A part of the recording head H1001 in Example 1 is shown in a broken state in FIG. 11, and the planar shape of the main part of the substrate unit is shown in FIG. 12, and its XIII-XIII arrow sectional structure, XIV-XIV arrow sectional structure Are shown in FIGS. 13 and 14, respectively. That is, 11 is a substrate as a recording element substrate H1100 on which the electrothermal conversion element 18 is provided, and the electrothermal conversion element 18 is formed by the heating resistor layer 13 positioned between the pair of electrode wirings 14a and 14b. . Reference numeral 15 denotes a step formed by a pair of electrode wirings 14a and 14b and rising from the heating resistor layer 13, 17 denotes a first protective layer, and 16 denotes a second protective layer. Reference numeral 19 denotes an ejection port for ejecting ink droplets, which corresponds to the ejection port H1100T described above. Reference numeral 20 denotes an ink chamber for supplying ink to the discharge ports 19, and 21 denotes an ink supply port that opens in the substrate 11 for supplying ink to the ink chamber 20, and corresponds to the ink supply port H1201 described above.
[0121]
The substrate 11 is usually anisotropically formed by patterning the heating resistor layer 13 and the pair of electrode wirings 14a and 14b on a Si wafer by a photolithography technique, and forming the ink chamber 20 and the discharge port 19 with a photosensitive resin. After the ink supply port 21 is formed by etching or the like, it is formed by cutting the Si wafer. Then, an electrical wiring substrate H1300 (see FIG. 5) that transfers an electrical signal for driving the electrothermal transducer 18 is connected to the substrate 11 by a mounting technique. That is, on this electric wiring substrate H1300, a power transistor for switching current to the electrothermal transducer 18 and a CMOS logic circuit for controlling this power transistor are formed using semiconductor technology as a driving means, and electrode wiring It is connected to the electrothermal conversion element 18 through 14a and 14b.
[0122]
In this embodiment, two rows of ejection ports 19 that are parallel to each other across the ink supply port 21 are arranged in a so-called zigzag pattern with a half pitch shift, and the ink chambers 20 corresponding to the ejection ports 19 in each row. Are arranged at a pitch of 600 dpi.
[0123]
Each ink chamber 20 is provided with an electrothermal conversion element 18 so that an ink droplet of 4 picoliters can be ejected from the ejection port 19.
[0124]
In this embodiment, an Si wafer is used as the substrate 11, and this Si wafer is thermally oxidized to an SiO of about several μm.₂An oxide layer 12 that is a film is formed. Thereafter, the heating resistor layer 13 is formed with a thickness of about 500 mm by sputtering. In this embodiment, TaN is used as the heating resistor layer 13, but HfB₂Or TaSiN may be used. Then, after forming the Al layer as the electrode wirings 14a and 14b with a thickness of 2100 mm and with a tolerance of ± 300 mm, the wiring region is patterned using a mask. In this embodiment, Al is used for the electrode wirings 14a and 14b, but an alloy such as Al-Si, Al-Cu, or Al-Si-Cu may be used. Then, the heating resistor layer 13 and the electrode wirings 14a and 14b are simultaneously etched by dry etching, and then patterning is performed using a mask in order to form a portion of the electrothermal conversion element 18, and then the electric heating The Al layer in the conversion element 18 is removed by wet etching.
[0125]
As described above, the film thickness of the electrode wirings 14a and 14b is reduced to about 2100 mm. However, reducing the film thickness of the electrode wirings 14a and 14b increases the wiring resistance. Since the consumption increases and the temperature of the substrate 11 is further increased, the electrode wirings 14a and 14b have conventionally been made thicker.
[0126]
However, when the wiring resistance is compared with the resistance value of the heating resistor layer 13, the ratio of the wiring resistance is insignificant, and reducing the film thickness as in the present invention is an aspect of power loss and temperature rise. Therefore, it is not a big problem, and on the contrary, the effect of improvement in power saving, thermal responsiveness and durability of the heating resistor layer 13 can be achieved by reducing the thickness of the first protective layer 17 covering the heating resistor layer 13. It was proved by verification by this example that this is much larger.
[0127]
The minimum value of the film thickness of the electrode wirings 14a and 14b is determined from the viewpoint of the current density of how much current is supplied for how long in the unit cross-sectional area determined by the width and film thickness. The It is generally well known that when the current density is high and the energization time is long, the resistance value of the material constituting the electrode wiring materials 14a and 14b increases due to electromigration.
[0128]
However, the number of times that the electrode wirings 14a and 14b formed on the substrate 11 can be energized is 3 × 10.⁸To 1 × 10⁹The energization time for one time is a very short time of about 1 μm, and the repetition drive frequency is about 30 kHz.
[0129]
When the electromigration of the electrode wirings 14a and 14b described above was evaluated using the substrate 11 in this example, the current density was 1.5 × 10.⁷A / cm, energization pulse width 1.3 μs, substrate 11 temperature kept constant at 60 ° C. 3 × 10⁹An energization test was conducted up to the pulse, but no phenomenon showing changes in the resistance values of the electrode wirings 14a and 14b was observed.
[0130]
After the formation of the electrode wirings 14a and 14b as described above, the first protective layer 17 made of SiN is formed by the CVD method. The first protective layer 17 of SiN is formed with a film thickness of 3000 mm and a tolerance of ± 400 mm, but silicon oxide can also be formed as the first protective layer 17.
[0131]
Next, Ta was formed as the second protective layer 16 by sputtering. The film thickness was 2300 mm, and the film was formed within a tolerance range of ± 280 mm. Instead of Ta, TaN, TaSiN or the like may be employed as the second protective layer 16.
[0132]
Next, in order to remove an unnecessary portion of Ta, which is the second protective layer 16, patterning is performed again, and then removed by a dry etching method. This dry etching time is set by applying the second protection to the recesses 22 between the heating resistor layers 13 (and the electrode wirings 14a and 14b that are alternately overlapped with each other) arranged in parallel along the arrangement direction of the electrothermal transducers 18. The overetching state is set so that the layer 16 does not remain. When the second protective layer 16 remains, if there is a pinhole in the first protective layer 17 below the portion where the second protective layer remains (hereinafter also referred to as “residual portion”), the wiring electrode and the residual portion are energized. The remaining part is oxidized. Here, when energizing the second protective layer 16 that the remaining portion has left as necessary, the necessary portion of the second protective layer 16 may be oxidized, and cavitation protection may not be possible. Therefore, in order to remove unnecessary portions of the second protective layer 16 without leaving them, it is preferable that the amount of overetching is 100 mm or more. Further, due to such over-etching, the thickness of the first protective layer 17 in the region where the second protective layer 16 has been removed becomes thinner than the thickness of the region where Ta constituting the second protective layer 16 exists. However, in order to reliably protect the electrode wiring, the difference is preferably 200 mm or less.
[0133]
In this dry etching, the etching gas injection direction is set to be perpendicular to the surface of the substrate 11, for example, so that the heating resistor layer 13 and the electrode wirings 14 a and 14 b overlapping therewith form the surface of the substrate 11 ( In the illustrated example, the first protective layer 17 in the portion of the step portion 23 rising from the surface of the oxide layer 12 is inclined with respect to the etching gas injection direction, and even if there is a crack, the intrusion of the etching gas As a result, the electrode wirings 14a and 14b that overlap the heating resistor layer 13 are not damaged. However, if the first protective layer 17 is excessively etched by over-etching, the electrode wirings 14a and 14b may be damaged because the step 23 having a rough film quality is etched quickly.
[0134]
By performing such anisotropic dry etching, even if the first protective layer 17 in the portion of the stepped portion 23 rising from the surface of the substrate 11 is cracked, the electrode wiring 14a that overlaps the heating resistor layer 13 is formed. , 14b is less likely to be damaged.
[0135]
On the other hand, FIG. 15 shows the state of the substrate surface when the unnecessary portion of the second protective layer 16 described above is performed by wet etching, and FIG. 16 shows the XVI-XVI arrow sectional structure. The members having the same functions as those in the example are denoted by the same reference numerals. That is, when unnecessary portions of the second protective layer 16 are removed by wet etching, the etching solution penetrates from the cracks present in the first protective layer 17 in the step portion 23 and etches the electrode wirings 14a and 14b. It has been found that the portion 24 is formed. However, when the unnecessary portion of the second protective layer 16 is removed by dry etching as in the present embodiment, the electrode wiring 14a as described above regardless of the presence of pinholes, cracks, or the like in the first protective layer 17. , 14b can be prevented from being etched.
[0136]
Further, when the overetching state is performed by the dry etching described above, the vicinity of the boundary between the first protective layer portion covered by the second protective layer and the first protective layer portion not covered by the second protective layer The portions of the first protective layer and the second protective layer can be tapered. The taper shape will be described later in Example 2.
[0137]
A recording head H1001 incorporating the substrate unit made in this way was created, and the number of repeated ink discharge durability was evaluated. 3 × 10⁸1 × 10 is the target number of service life.⁹Even when repeated, no problems such as disconnection of the heating resistor layer 13 occurred. The film thickness of the first protective layer 17 was approximately 1.14 times the film thickness of the electrode wirings 14a and 14b in the recording head H1001 used in this test.
[0138]
(Example 2)
FIG. 17 shows the planar shape of the main part of the liquid ejection head in Example 2, and FIG. 18 shows the cross-sectional structure taken along the line XVIII-XVIII. Here, 25 is a discharge port forming member for forming a discharge port, and 26 is an adhesion layer for improving the adhesion between the substrate and the discharge port forming member. The substrate bonded to the discharge port forming member corresponds to the recording element substrate H1100. Other configurations and effects are substantially the same as those in the first embodiment.
[0139]
The liquid discharge head shown in FIGS. 17 and 18 is manufactured by forming the adhesion layer 26 and the discharge port forming member 25 on the liquid discharge head substrate unit 27 substantially the same as that described in the first embodiment.
[0140]
First, a polyetheramide resin having a thickness of 2.0 μm was formed as the adhesion layer 26 on the liquid discharge head substrate unit 27 substantially the same as that described in Example 1 by the following method. For this polyetheramide resin, HIMAL1200 manufactured by Hitachi Chemical Co., Ltd. was used and applied onto the substrate unit 27 with a spinner and baked at 100 ° C./30 minutes + 250 ° C./1 hour.
[0141]
Next, patterning is performed on the HIMAL using a positive resist OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd., and further using the OFPR pattern as a mask.₂The HIMAL layer was patterned by plasma ashing, and finally the OFPR pattern used as a mask was peeled off to form the adhesion layer 26 as shown in FIGS.
[0142]
Next, a positive resist ODUR, which is a soluble photosensitive material, was applied on the substrate unit, and an ink flow path pattern (not shown) was patterned (thickness 12 μm).
[0143]
Further, a coating resin layer was formed on the substrate unit 27 as the discharge port forming member 25, and the discharge port 19 was formed by patterning. The coating resin layer is preferably photosensitive because the discharge port 19 can be easily and accurately formed by photolithography. Moreover, since it is requested | required to have adhesiveness with the board | substrate unit 27, and ink resistance, what uses the cationic polymerization hardened | cured material of an epoxy resin as a structural material was used.
[0144]
Next, the SiN film on the ink supply port 21 is removed by CDE (Chemical Dry Etching), and the ODUR is removed by immersing it in a solution, whereby the ink flow path pattern composed of the SiN film on the ink supply port 21 and ODUR. In addition, in order to completely cure the epoxy resin as the discharge port forming member 25, heating was performed at 180 ° C. for 1 hour to obtain a liquid discharge head.
[0145]
Furthermore, heating was performed at 180 ° C. for 1 hour in order to completely cure the epoxy resin that is the discharge port forming member 25, thereby obtaining a liquid discharge head.
The discharge port forming member 25 is bonded to a part of the second protective layer 16 and a part of the first protective layer 17 not covered by the second protective layer 16 through an adhesion layer as shown in FIGS. Has been. Thus, the adhesion between the discharge port forming member 25 and the substrate unit 27 on which the first protective layer 17 and the second protective layer 16 are formed is improved by using the adhesion layer 26.
[0146]
In this embodiment, as described below, by further improving the adhesion, peeling of the discharge port forming member 25 can be prevented, and the reliability of the liquid discharge head can be improved.
[0147]
As described in the first embodiment, when the substrate unit is manufactured, the thickness of the portion of the first protective layer 16 not covered with the second protective layer 16 is set to the first protective layer 17 covered with the second protective layer 16. When the thickness of the first protective layer 17 is smaller than the thickness of the first protective layer 17, the first protective layer 17 covered by the second protective layer 16 and the portion of the first protective layer 17 not covered by the second protective layer 16 are in the vicinity of the boundary. A side wall 28 is formed not only by the second protective layer 16 but also by the first protective layer 17. As a result, in the liquid ejection head manufactured by forming the adhesion layer 26 and the ejection port forming member 25 on the substrate unit 27, the adhesion between the first protective layer 17 and the adhesion layer 26 in the vicinity of the second protective layer 16. And the peeling of the discharge port forming member 25 is less likely to occur.
[0148]
Here, when the side wall 28 is formed by being over-etched by dry etching, the side wall 28 can be tapered. FIG. 13 described in the first embodiment is an embodiment where the angles of the tapered shapes of the first protective layer 17 and the second protective layer 16 are substantially equal. FIG. 18 shows an example in which the inclination of the tapered shape of the first protective layer 17 is gentler than the tapered shape of the second protective layer 16. Further, the taper shape may have a curvature. In order to further improve the adhesion, the steeper angle inclination of the first protective layer and the second protective layer is better.
[0149]
(Other examples)
In the first and second embodiments, the side shooter type recording head H1001 in which the discharge port 19 and the electrothermal conversion element 18 face each other has been described. However, the opening direction of the discharge port is substantially orthogonal to the surface of the electrothermal conversion element. The present invention can also be applied to an edge shooter type inkjet head.
[0150]
The appearance of another embodiment of the liquid discharge head according to the present invention is shown in FIG. 19, but the members having the same functions as those of the previous embodiment are designated by the same reference numerals, and redundant description is omitted. And That is, the grooved member 25 is bonded onto the substrate 11, and the discharge ports 19 arranged at a predetermined interval with the substrate 11, and the common ink chamber 27 that communicates with the discharge ports 19 via the ink paths 26, respectively. In addition, an ink supply port 28 for supplying ink to the common ink chamber 27 is formed. The ink supplied from the ink supply port 28 into the common ink chamber 27 causes film boiling by the electrothermal transducer 18 in the ink path 26 and is discharged as ink droplets from the discharge port 19. .
[0151]
Also in the present embodiment, the electrothermal transducer 18 formed on the substrate 11 has the same configuration as the above-described embodiment.
[0152]
【The invention's effect】
  According to the present invention, the first protective layer that is formed over almost the entire surface of the substrate and covers the pair of electrode wirings and the electrothermal conversion element, and the electrothermal conversion element formed on the surface of the first protective layer and the A second protective layer that covers the vicinity of the connection portion between the electrothermal conversion element and the pair of electrode wirings is provided, the thickness of the pair of electrode wirings is within a range of 1800 to 2400 mm, and the first protection layer is covered with the second protective layer Layer thickness within the range of 2600-3400mmAnd thenOf the first protective layer not covered by the second protective layerUniform film thicknessSince the thickness of the portion is made thinner than the thickness of the portion of the first protective layer covered with the second protective layer, the first protective layer can be uniformly thin without adding a film forming step or using a mask. Can be. In addition, the coverage of the first protective layer in the stepped portion formed by the electrode wiring and rising from the surface of the substrate can be kept good.
[0153]
As a result, the liquid can be rapidly heated and the foaming stability can be improved. As a result, it is possible to save power and suppress the temperature rise of the liquid discharge head. It is possible to improve the driving frequency and realize a high-quality printing operation. In addition, a highly reliable liquid discharge head having excellent discharge durability of the electrothermal conversion element can be obtained with the same man-hours as before.
[0154]
In particular, when the thickness of the pair of electrode wirings is in the range of 2000 to 2200 mm, the thickness of the first protective layer can be made even thinner and protected by partial concentration of thermal stress accompanying repeated heat generation. A crack is generated in the layer, and a disconnection accident in which the liquid enters from the cracked part and breaks the heating resistance layer can be prevented, and the durability can be improved.
[0155]
An electrothermal conversion element and a second protective layer that covers the vicinity of the connection portion between the electrothermal conversion element and the pair of electrode wirings are formed on the surface of the first protective layer by dry etching, so that the second protective layer covers the electrothermal conversion element. When the thickness of the portion of the first protective layer that is not covered is made thinner than the thickness of the portion of the first protective layer covered by the second protective layer, and the thickness of the pair of electrode wirings is in the range of 1800 to 2400 mm Can prevent the electrothermal conversion element and the electrode wiring from being damaged.
[0156]
Further, by forming the portions of the first protective layer and the second protective layer that are covered with the discharge port forming member into a tapered shape, the adhesion between the first protective layer and the discharge port forming member in the vicinity of the second protective layer is improved. The discharge port forming member is less likely to peel off.
[0157]
For this reason, the first protective layer exposed by removing the second protective layer with respect to the electrothermal conversion element, the pair of electrode wirings, the driving element provided on the substrate, and the like is exposed to moisture or in a high humidity environment. , Can exert a sufficient function.
[0158]
When at least two rows of ejection ports are formed in parallel to each other and are arranged at intervals of 600 dpi, and these arrangement intervals for each row are shifted from each other by a half pitch, a high-performance liquid ejection head of 1200 dpi is obtained. Can do.
[0159]
When the discharge amount of the liquid discharged from the discharge port discharged by the drive pulse applied independently to the electrothermal conversion element is 4 picoliters, the image quality obtained by improving the resolution of the image is greatly improved. be able to.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external configuration of an ink jet printer according to an embodiment of the present invention.
2 is a perspective view showing a state in which an exterior member of what is shown in FIG. 1 is removed. FIG.
FIG. 3 is a perspective view showing a state in which the recording head cartridge used in the embodiment of the invention is assembled.
4 is an exploded perspective view showing the recording head cartridge shown in FIG. 3. FIG.
5 is an exploded perspective view of the recording head shown in FIG. 4 as viewed obliquely from below.
FIG. 6 is a perspective view showing a scanner cartridge according to an embodiment of the present invention.
FIG. 7 is a block diagram schematically showing an overall configuration of an electrical circuit in an embodiment of the present invention.
8 is a block diagram showing an internal configuration of the main PCB shown in FIG. 7;
9 is a block diagram showing an internal configuration of the ASIC shown in FIG.
FIG. 10 is a flowchart showing the operation of the exemplary embodiment of the present invention.
FIG. 11 is a cutaway perspective view showing a schematic structure of an embodiment of a liquid discharge head according to the present invention.
12 is a plan view of the main part of the substrate in the embodiment shown in FIG. 11. FIG.
13 is a cross-sectional view taken along arrow XIII-XIII in FIG.
14 is a cross-sectional view taken along arrow XIV-XIV in FIG.
FIG. 15 is a plan view of the main part of the substrate when the second protective layer is formed by wet etching.
16 is a cross-sectional view taken along arrow XVI-XVI in FIG.
FIG. 17 is a plan view of the main part of another embodiment of the liquid ejection head according to the present invention.
18 is a cross-sectional view taken along arrow XVIII-XVIII in FIG.
FIG. 19 is a perspective view showing a part of the appearance of another embodiment of the liquid discharge head according to the present invention.
FIG. 20 is a cross-sectional view showing an example of the structure of a substrate of a conventional inkjet head.
FIG. 21 is a cross-sectional view showing another example of the structure of a substrate of a conventional inkjet head.
FIG. 22 is a cross-sectional view showing another example of the structure of a substrate of a conventional inkjet head.
[Explanation of symbols]
  11 Substrate (Recording Element Substrate H1100)
  12 Oxide layer
  13 Heating resistor layer
  14a, 14b Electrode wiring
  15 steps
  16th2Protective layer
  17th1Protective layer
  18 Electrothermal conversion element
  19 Discharge port (H1100T)
  20 Ink chamber
  21 Ink supply port (H1201)
  22 recess
  23 steps
  24 Defects
  25 Discharge port forming member
  26 Adhesive layer
  27 Board unit
  28 side walls
  M1000 main unit
  M1001 Lower case
  M1002 Upper case
  M1003 Access cover
  M1004 discharge tray
  M2015 Paper gap adjustment lever
  M2003 Paper discharge roller
  M3001 LF roller
  M3019 chassis
  M3022 Automatic feeding section
  M3029 transport section
  M3030 discharge section
  M4001 Carriage
  M4002 Carriage cover
  M4007 Headset lever
  M4021 Carriage shaft
  M5000 recovery unit
  M6000 scanner
  M6001 Scanner holder
  M6003 Scanner cover
  M6004 Scanner contact PCB
  M6005 Scanner illumination lens
  M6006 Scanner reading lens 1
  M6100 storage box
  M6101 storage box base
  M6102 Storage box cover
  M6103 Storage box cap
  M6104 Storage box spring
  E0001 Carriage motor
  E0002 LF motor
  E0003 PG motor
  E0004 Encoder sensor
  E0005 Encoder Scale
  E0006 Ink end sensor
  E0007 PE sensor
  E0008 GAP sensor (Paper gap sensor)
  E0009 ASF sensor
  E0010 PG sensor
  E0011 Contact FPC (Flexible Print Cable)
  E0012 CRFFC (flexible flat cable)
  E0013 Carriage board
  E0014 main board
  E0015 Power supply unit
  E0016 Parallel I / F
  E0017 Serial I / F
  E0018 Power key
  E0019 Resume key
  E0020 LED
  E0021 Buzzer
  E0022 Cover sensor
  E1001 CPU
  E1002 OSC (CPU built-in oscillator)
  E1003 A / D (A / D converter with built-in CPU)
  E1004 ROM
  E1005 Oscillator circuit
  E1006 ASIC
  E1007 Reset circuit
  E1008 CR motor driver
  E1009 LF / PG motor driver
  E1010 Power supply control circuit
  E1011 INKS (ink end detection signal)
  E1012 TH (Thermistor temperature detection signal)
  E1013 HSENS (Head detection signal)
  E1014 Control bus
  E1015 RESET (Reset signal)
  E1016 RESUME (resume key input)
  E1017 POWER (Power key input)
  E1018 BUZ (Buzzer signal)
  E1019 Oscillator circuit output signal
  E1020 ENC (encoder signal)
  E1021 Head control signal
  E1022 VHON (Head power ON signal)
  E1023 VMON (motor power ON signal)
  E1024 Power control signal
  E1025 PES (PE detection signal)
  E1026 ASFS (ASF detection signal)
  E1027 GAPS (GAP detection signal)
  E0028 Serial I / F signal
  E1029 Serial I / F cable
  E1030 Parallel I / F signal
  E1031 Parallel I / F cable
  E1032 PGS (PG detection signal)
  E1033 PM control signal (pulse motor control signal)
  E1034 PG motor drive signal
  E1035 LF motor drive signal
  E1036 CR motor control signal
  E1037 CR motor drive signal
  E0038 LED drive signal
  E1039 VH (head power supply)
  E1040 VM (motor power supply)
  E1041 VDD (logic power supply)
  E1042 COVS (Cover detection signal)
  E2001 CPU I / F
  E2002 PLL
  E2003 DMA controller
  E2004 DRAM controller
  E2005 DRAM
  E2006 1284 I / F
  E2007 USB I / F
  E2008 Reception control unit
  E2009 Compression and decompression DMA
  E2010 Receive buffer
  E2011 Work buffer
  E2012 Work area DMA
  E2013 Recording buffer transfer DMA
  E2014 Print buffer
  E2015 Recording data expansion DMA
  E2016 Data buffer for decompression
  E2017 Column buffer
  E2018 Head control unit
  E2019 Encoder signal processor
  E2020 CR motor controller
  E2021 LF / PG motor controller
  E2022 Sensor signal processor
  E2023 Motor control buffer
  E2024 Scanner capture buffer
  E2025 Scanner data processing DMA
  E2026 Scanner data buffer
  E2027 Scanner data compression DMA
  E2028 Sending buffer
  E2029 Port control unit
  E2030 LED controller
  E2031 CLK (clock signal)
  E2032 PDWM (software control signal)
  E2033 PLLON (PLL control signal)
  E2034 INT (interrupt signal)
  E2036 PIF received data
  E2037 USB reception data
  E2038 WDIF (received data / raster data)
  E2039 Reception buffer control unit
  E2040 RDWK (Reception buffer read data / raster data)
  E2041 WDWK (work buffer write data / record code)
  E2042 WDWF (Workfill data)
  E2043 RDWP (work buffer read data / record code)
  E2044 WDWP (Sort recording code)
  E2045 RDHDG (data for recording development)
  E2047 WDHDG (column buffer write data / development record data)
  E2048 RDHD (column buffer read data / development record data)
  E2049 Head drive timing signal
  E2050 Data development timing signal
  E2051 RDPM (pulse motor drive table read data)
  E2052 Sensor detection signal
  E2053 WDHD (captured data)
  E2054 RDAV (acquisition buffer read data)
  E2055 WDAV (data buffer write data / processed data)
  E2056 RDYC (data buffer read data / processed data)
  E2057 WDYC (send buffer write data / compressed data)
  E2058 RDUSB (USB transmission data / compressed data)
  E2059 RDPIF (1284 transmission data)
  H1000 recording head cartridge
  H1001 Recording head
  H1100 recording element substrate
  H1100T Discharge port
  H1200 first plate
  H1201 Ink supply port
  H1300 Electric wiring board
  H1301 External signal input terminal
  H1400 second plate
  H1500 tank holder
  H1501 ink flow path
  H1600 flow path forming member
  H1700 filter
  H1800 seal rubber
  H1900 ink tank

Claims (23)

A substrate unit used in a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port,
An electrothermal conversion element for generating thermal energy formed on the surface of the substrate;
A pair of electrode wirings formed on the surface portion of the substrate so as to be electrically connected to the electrothermal conversion element;
A first protective layer formed over substantially the entire surface of the substrate and covering the pair of electrode wirings and the electrothermal transducer;
A second protective layer formed on a surface of the first protective layer and covering a vicinity of a connection portion between the electrothermal conversion element and the electrothermal conversion element and the pair of electrode wirings;
The thickness of the pair of electrode wires is in the range of 1800 to 2400 mm,
The thickness of the portion of the first protective layer covered by the second protective layer is in the range of 2600-3400 mm,
The first protective layer has a portion having a uniform thickness that is not covered by the second protective layer ,
The substrate unit for a liquid discharge head, wherein the thickness of the portion having the uniform thickness of the first protective layer is smaller than the thickness of the portion of the first protective layer covered with the second protective layer.   2. The liquid discharge head substrate unit according to claim 1, wherein a thickness of the pair of electrode wirings is preferably in a range of 2000 to 2200 mm. 3. Wherein the thickness of the film thickness uniform portion of the first protective layer a second not covered by the protective layer, the difference between the thickness of the portion of said covered by the second protective layer the first protective layer, 200 Å The substrate unit for a liquid discharge head according to claim 1, wherein the substrate unit is a liquid discharge head substrate unit. The difference between the thickness of the uniform part of the first protective layer not covered by the second protective layer and the thickness of the part of the first protective layer covered by the second protective layer is 100 mm. 4. The liquid discharge head substrate unit according to claim 1, wherein the liquid discharge head substrate unit is as described above.   5. The liquid discharge head substrate unit according to claim 1, wherein a thickness of the first protective layer is 1.08 times or more a thickness of the pair of electrode wirings. The liquid discharge head substrate unit according to any one of claims 1 to 5, wherein the first protective layer is made of SiN. 7. The liquid discharge head substrate unit according to claim 1, wherein the second protective layer is made of Ta, TaN, or TaSiN. A method of manufacturing a substrate unit used in a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port,
Forming an electrothermal conversion element for generating thermal energy on the surface of the substrate;
Forming a pair of electrode wirings on the surface of the substrate so as to conduct to the electrothermal conversion element;
Forming a first protective layer having a thickness of 2600 to 3400 mm covering the pair of electrode wirings and the electrothermal conversion element over substantially the entire surface portion of the substrate;
The second protection layer is formed on the surface of the first protection layer by dry etching so as to cover the electrothermal conversion element and the vicinity of the connection portion between the electrothermal conversion element and the pair of electrode wirings. Making the thickness of the portion of the first protective layer not covered by the layer thinner than the thickness of the portion of the first protective layer covered by the second protective layer,
A method of manufacturing a substrate unit for a liquid discharge head, wherein the thickness of the pair of electrode wirings is in a range of 1800 to 2400 mm. The second protective layer in forming the dry etching to claim 8 in which the thickness to be etched portion of said first protective layer not covered by said second protective layer is equal to or is within 200Å The manufacturing method of the substrate unit for liquid discharge heads of description. The second protective layer in forming the dry etching according to claim 8 thickness to be etched portion of the second is not covered by the protective layer and the first protective layer is equal to or is 100Å or more or A method for manufacturing a substrate unit for a liquid discharge head according to claim 9 . A liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port.
An electrothermal conversion element that generates thermal energy for forming film boiling in the liquid formed on the substrate;
A pair of electrode wirings formed on the substrate and conducting to the electrothermal transducer;
A first protective layer formed over substantially the entire surface of the substrate and covering the pair of electrode wirings and the electrothermal transducer;
A second protective layer formed on a surface of the first protective layer and covering a vicinity of a connection portion between the electrothermal conversion element and the electrothermal conversion element and the pair of electrode wirings;
The thickness of the pair of electrode wires is in the range of 1800 to 2400 mm,
The thickness of the portion of the first protective layer covered by the second protective layer is in the range of 2600-3400 mm,
The first protective layer has a portion having a uniform thickness that is not covered by the second protective layer ,
The liquid discharge head according to claim 1, wherein the thickness of the portion having the uniform thickness of the first protective layer is thinner than the thickness of the portion of the first protective layer covered with the second protective layer. Liquid ejection according to 請 Motomeko 1 1 you, wherein the discharge amount per one liquid from the discharge port to be discharged by the drive pulse applied to said electrothermal converting element is less than 5 picoliters head. A discharge port forming member for forming the discharge port;
The discharge port forming member is bonded to a part of the second protective layer and a part of the first protective layer not covered with the second protective layer via an adhesion layer. The liquid discharge head according to claim 11 or 12 .   The first protective layer and the second protection in the vicinity of the boundary between the portion of the first protective layer covered by the second protective layer and the portion of the first protective layer not covered by the second protective layer The liquid discharge head according to claim 13, wherein a portion of the layer has a tapered shape. The liquid ejection head according to claim 14, wherein the taper shape has a gentler inclination in the taper-shaped angle of the first protective layer than in the taper-shaped angle of the second protective layer.   The liquid discharge head according to claim 13, wherein the adhesion layer is a polyetheramide resin.   The liquid discharge head according to any one of claims 13 to 16, wherein the discharge port forming member is formed of a cationic polymerization cured product of an epoxy resin.   The liquid discharge head according to claim 13, wherein the discharge port is provided on an opposite side of the electrothermal conversion element. The first protective layer is S i The liquid discharge head according to claim 11, comprising N. The second protective layer is T a Or T a N or T a S i The liquid ejection head according to claim 11, wherein the liquid ejection head is made of N. A cartridge having a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port,
An electrothermal conversion element that is formed on the substrate and generates thermal energy for causing film boiling in the liquid; a pair of electrode wirings that are formed on the substrate and that conduct to the electrothermal conversion element; and a surface portion of the substrate A first protective layer having a thickness that covers the pair of electrode wirings and the electrothermal conversion element, and the electrothermal conversion element and the electrothermal conversion element formed on the surface of the first protective layer. And a liquid discharge head having a second protective layer covering the vicinity of the connection portion between the pair of electrode wirings,
A liquid tank for storing liquid supplied to the liquid discharge head,
The thickness of the pair of electrode wires is in the range of 1800 to 2400 mm,
The thickness of the portion of the first protective layer covered by the second protective layer is in the range of 2600-3400 mm,
The first protective layer has a portion having a uniform thickness that is not covered by the second protective layer ,
The cartridge having a uniform thickness of the first protective layer is thinner than a thickness of the portion of the first protective layer covered with the second protective layer. The cartridge according to claim 21 , wherein the liquid tank is detachably mounted on the liquid discharge head. An image forming apparatus using a liquid discharge head that applies thermal energy to a liquid to cause film boiling, thereby discharging liquid droplets from a discharge port.
An electrothermal conversion element that generates thermal energy for causing film boiling in the liquid formed on the substrate, a pair of electrode wirings formed on the substrate and conducting to the electrothermal conversion element, and a surface portion of the substrate A first protective layer that is formed over substantially the entire area and covers the pair of electrode wirings and the electrothermal conversion element; and the electrothermal conversion element, the electrothermal conversion element, and the pair that are formed on the surface of the first protective layer. e sushi mounting portion of the liquid ejection head having a an electrode wire second protective layer which covers the connecting portion vicinity of,
When the thickness of the pair of electrode wires is Ri range near the 1800～2400A,
The thickness of the portion of the first protective layer covered by the second protective layer is in the range of 2600-3400 mm,
The first protective layer has a portion having a uniform thickness that is not covered by the second protective layer ,
2. An image forming apparatus according to claim 1, wherein the thickness of the first protective layer having a uniform thickness is smaller than the thickness of the portion of the first protective layer covered by the second protective layer.

Images